Main content

Puzzle for Today

Puzzle No. 161 – Tuesday 13 February

You have one hundred 5 ml samples of blood and know that up to nine could be carrying a particularly nasty disease. Luckily, there is a test for the disease that requires only 1 ml of diseased blood. What is the maximum number of tests that must be performed to identify all diseased samples?

Today's #PuzzleForToday has been set by the School of Mathematics at The University of Manchester

The Answer will be available for a week.

More fiendish brain-teasers and quizzes on BBC Radio...